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Forecasting and trading cryptocurrencies with machine learning under changing market conditions

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Financial Innovation 2021年第1期7卷 61-90页

作者： Helder Sebastiao Pedro Godinho univ coimbra CeBERFaculty of EconomicsAv.Dr.Dias da Silva1653004‑512 CoimbraPortugal

This study examines the predictability of three major cryptocurrencies—bitcoin,ethereum,and litecoin—and the profitability of trading strategies devised upon machine learning techniques(e.g.,linear models,random forests,and support vector machines).The models are validated in a period characterized by unprecedented turmoil and tested in a period of bear markets,allowing the assessment of whether the predictions are good even when the market direction changes between the validation and test *** classification and regression methods use attributes from trading and network activity for the period from August 15,2015 to March 03,2019,with the test sample beginning on April 13,*** the test period,five out of 18 individual models have success rates of less than 50%.The trading strategies are built on model *** ensemble assuming that five models produce identical signals(Ensemble 5)achieves the best performance for ethereum and litecoin,with annualized Sharpe ratios of 80.17%and 91.35%and annualized returns(after proportional round-trip trading costs of 0.5%)of 9.62%and 5.73%,*** positive results support the claim that machine learning provides robust techniques for exploring the predictability of cryptocurrencies and for devising profitable trading strategies in these markets,even under adverse market conditions.

关键词： Bitcoin Ethereum Litecoin Machine learning Forecasting Trading

The role of physical properties in explosive welding of copper to stainless steel

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Defence Technology（防务技术） 2023年第4期22卷 88-98页

作者： G.H.S.F.L.Carvalho I.Galvao R.Mendes R.M.Leal A.B.Moreira A.Loureiro univ coimbra CEMMPREDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal Department of Industrial Engineering University of FirenzeVia di Santa Marta 350139FirenzeItaly ISEL Departamento de Engenharia Mec^anicaInstituto Politecnico de LisboaRua Conselheiro Emídio Navarro 11959-007LisboaPortugal univ coimbra ADAILEDAPDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal LIDA-ESAD.CR Instituto Politecnico de LeiriaRua Isidoro Inacio Alves de Carvalho2500-321Caldas da RainhaPortugal univ.Porto LAETA/INEGIDept.Eng.Metalúrgica e de MateriaisR.Dr.Roberto Frias4200-465PortoPortugal

This paper investigates the effects of the physical properties on the microstructure and weldability of explosive welding by joining two metals with a significant contrast in thermophysical properties:stainless steel and *** welds between stainless steel and copper were obtained,and the interfacial morphology was wavy,regardless of the position of the *** weldability of dissimilar pairs was found to be more dependent on the relationship between the physical properties of the base materials than on the absolute value of the material *** there is a significant difference in thermal conductivity between the flyer and the base plate,together with a material with a low melting temperature,the weldability of the pair is often *** relative position of the plates affects the interfacial microstructure even when similar morphologies are *** the metallic pairs studied,the wave size was bigger for the configuration in which the ratio between the density of the flyer and the density of the base plate is *** same phenomenon was observed for the impedance:bigger waves were found for a smaller ratio between the impedance of the flyer and the impedance of the base plate.

关键词： Explosive welding Solid-state Copper-stainless steel Dissimilar Interface morphology Weldability

Translational machinery and translation regulation in axon regeneration

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Neural Regeneration Research 2025年第5期20卷 1392-1394页

作者： Homaira Nawabi Stephane Belin univ.Grenoble Alpes InsermU1216Grenoble Institut NeurosciencesGrenobleFrance

Over the centuries,the regeneration field has been puzzled by the dual response of the central nervous system(CNS-brain,spinal cord,cranial nervesⅠandⅡ)and the peripheral nervous system(PNS that refers to all the nerves that innervate muscles,skin,organs,bones among others).Even Ramon y Cajal had noticed that an injury to the PNS often leads to axon regrowth,in contrast to the CNS.

关键词： nerves organs muscles

Pleistocene Birds of Gruta da Furninha （Peniche-Portugal）： A Paleontological and Paleoenvironmental Aproach

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Journal of Environmental Science and Engineering(A) 2017年第10期6卷 502-509页

作者： Silverio Domingues Figueiredo Pedro Proenga Cunha Femanda Sousa Telmo Pereira Americo Rosa Polytechnic Institute of Tomar Quinta do Contador Estrada da Serra 2300-313 Tomar Portugal Portuguese Center of Geo-History and Prehistory Largo de Sao Caetano Golega 2150-265 Portugal Geosciences Center--univ. of coimbra Rua Silvio Lima Univ. Coimbra Coimbra 3030-790 Portugal MARE--Marine and Environmental Sciences Centre Department of Earth Sciences Coimbra University Rua Silvio LimaCoimbra 3030- 790 Portugal ICArEHB--Interdisciplinary Center for Archaeology and Evolution of Human Behaviour Human and Social Sciencies Faculty University of Algarve Campus de Gambelas 8005-139 Faro Portugal

The cave-site of Gruta da Furninha is a coastal karstic cavity. In the late 19th century, excavation of the sedimentary infill of the cave allowed the identification of two lithostratigraphic units： a Holocene one dominated by sands, containing human bones and a Neolithic industry; and a Late Pleistocene one, containing a diverse set of fossils set and Paleolithic artifacts. This study mainly focuses on taphonomic and palaeoenvironmental data concerning the Pleistocene bird bones that were collected from six layers （at 11 m and 6.7 m asl）. A main result of this study was the discovery of a left humerus fragment, with osteological features of the Alcidae family; from comparison with upper arms of distinct species of this family, it was concluded that this fossil belongs to Penguin impennis. The Pleistocene birds of the Furninha cave were also compared with the avifauna that currently occurs in the region of Peniche peninsula and a climate and environmental interpretation of the Pleistocene fossiliferous set is provided.

关键词： Birds Pleistocene marine caves Portugal.

Imidazolium-based ionic liquids as additives to preserve the Enhanced Green Fluorescent Protein fluorescent activity

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Green Chemical Engineering 2021年第4期2卷 412-422页

作者： Nathalia V.Veríssimo Carolina F.Saponi Timothy M.Ryan Tamar L.Greaves Jorge F.B.Pereira Department of Engineering of Bioprocesses and Biotechnology School of Pharmaceutical SciencesSao Paulo State University(UNESP)Rodovia Araraquara-Jaú/Km 0114800-903AraraquaraSPBrazil School of Science College of ScienceEngineering and HealthRMIT University124 La Trobe StreetMelbourneVIC 3000Australia School of Pharmaceutical Sciences Sao Paulo University(USP)Av.Prof.Lineu Prestesno.580B1605508-000Cidade de UniversitariaSao PauloSPBrazil Australian Synchrotron 800 Blackburn RoadClaytonVIC 3168Australia univ coimbra CIEPQPFDepartment of Chemical EngineeringRua Sílvio LimaPolo II–Pinhal de Marrocos3030-790 CoimbraPortugal

Fluorescent Proteins(FP)can be applied as biomarkers and biosensors in the industrial and medical fields,but their large-scale use,especially for new industrial applications,is limited due to their low ***,the discovery of additives capable of preserving the activity of FP at room temperature and under stress conditions can help to expand and facilitate their commercial *** this goal,we evaluated the application of 1-alkyl-3-methylimidazolium chloride-based([C_(n)mim]Cl)ionic liquids(ILs)as additives to preserve the activity of Enhanced Green Fluorescent Protein(EGFP)at different storage times and under unfavorable ***[C_(n)mim]Cl solutions(at 0.100 mol L^(-1))were able to preserve EGFP fluorescence for longer than the phosphatesaline buffer(PBS)and NaCl solutions,increasing its fluorescence manifestation from 1 to 3 months.[C_(n)mim]Cl with shorter to medium cationic alkyl chains were the most effective in preserving EGFP fluorescence.[C_(n)mim]Cl also protected EGFP activity in the presence of the surfactant SDS,the acid guanidine hydrochloride,and H_(2)O_(2).Therefore,[C_(n)mim]Cl can be added to aqueous solutions to preserve EGFP fluorescence activity at room temperature for longer storage times and to reduce the negative impact of denaturing agents on ***,there is a massive potential for the application of ILs as additives to preserve FP in the long-term without refrigeration and under unfavorable conditions,and this is fundamental to enable expansion of FP in industrial and commercial applications.

关键词： Green Fluorescent Protein Protein stability Fluorescence Ionic liquids Preservatives

Pleistocene Birds of Gruta Nova da Columbeira(Bombarral-Portugal):A Paleontological and Paleoenvironmental Aproach

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Journal of Environmental Science and Engineering(A) 2018年第6期7卷 246-254页

作者： Silvério D. Figueiredo Fernanda Sousa Solange Silva Luís Raposo Telmo Pereira Américo Rosa Polytechnic Institute of Tomar Quinta do ContadorEstrada da SerraTomar 2300-313Portugal Portuguese Center of Geo-History and Prehistory Largo de Sao CaetanoGolega 2150-265Portugal Geosciences Center Univ. of CoimbraRua Sílvio LimaUniv. CoimbraCoimbra 3030-790Portugal Departament of Earth Sciiences New University of Lisbon (FCT)Quinta da TorreCaparica 2829-516Portugal Nacional Museum of Arqueologia Praca do ImperioLisboa 1400-026Portugal ICArEHB Interdisciplinary Center for Archaeology and Evolution of Human Behaviour Human and Social Sciencies FacultyUniversity of AlgarveFaro 8005-139Portugal

Discovered in 1962,the Columbeira cave has a Mousterian sequence dated between 101 and 35 Ka(U-series)and between 28,900 and 18,000 BP *** recovered abundant lithic implements and provided rich assemblage of vertebrates,including mammals,reptiles,birds and a remain of Homo *** this work,authors present the taxonomy at the level of genus and species of the bird assemblage and its possible relationship with the paleoenvironments in which they *** species of birds have been identified out of 283 *** of these bones are very fragmented and unsuitable for identification down to species or the genus ***,it is possible to say that the species vary through the sequence and that the assemblage is dominated by Pyrrhocorax,Corvus,Columba Turdus and Alectoris.

关键词： Middle Paleolithic caves pleistocene birds Portugal

Deciphering the mechanobiology of microglia in traumatic brain injury with advanced microsystems

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Neural Regeneration Research 2025年第8期20卷 2304-2306页

作者： Anthony Procès Sylvain Gabriele univ.Grenoble Alpes InsermU1216Grenoble Institut des NeurosciencesGrenobleFrance Mechanobiology&Biomaterials Group CIRMAPResearch Institute for BiosciencesUniversity of MonsMonsBelgium

Advanced microsystems in traumatic brain injury research:Traumatic brain injury(TBI)results from a mechanical insult to the brain,leading to neuronal and axonal damage and subsequently causing a secondary *** minutes ... 详细信息

关键词： traumatic injury damage

ANALYSIS OF FRAZIL JAM DATA FROM HEQU REACH OF THE YELLOW RIVER

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Journal of Hydrodynamics 1994年第1期6卷 23-32页

作者： Wang De-sheng Sheng Hung-tao (Department of Civil and Environmental Engineering university, Potsdam, NY 13699-5710,U. S. A.)Sun Zhao-chu (Department of Civil Engineering, Hefei university of Technology, Hefei, 230009, P. R. China) Clarkson univ

The critical velocity, or critical Froude number criterion has long been accepted as a means of determining frazil jam profiles. Field observations, however, indicated that the value of the critical velocity not only varier from river reach to river reach but also from time to time in a given reach. This clearly shows the deficiency of the critical velocity concept. The transport of frazil particles on the underside of an ice cover is similar to the transport of bed sediments in an alluvial river; the difference being only that in one the buoyant force exceeds the gravity force ware in the other the reverse is true. Frazil particles are generally transported along the cover in the form of the cover load. In this peper, ice transport capacity for the Hequ reach of the Yellow River is analyzed. The analysis of field data shows that the ice transport capacity can ho described by existing bed load transport formulas for low density sediments.

关键词： ice cover ice discharge frail jam.

ION CHANNELING STUDIES OF HETEROEPITAXIAL STRUCTURES FORMED BY MOLECULAR BEAM

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Science in China,Ser.A 1988年第7期31卷 818-830页

作者：彭建良王广厚 Nanjing univ China Nanjing Univ China

Epitaxial growth of CaF2 films onto Si（111）substrates and the subsequent growth of si or Ge films onto the CaF2/Si（111） structure have been conducted with heteroepitaxial structures of Si/CaF2/Si（111） or Ge/CaF2/Si（111）, and then investigated by the Rutherford backscattering and ion channeling measurements. It is found that the Si film deposited on the CaF2 layer consists of the crystallites of two kinds: one with the orientation either the same as that of silicon substrate （A type） or rotating 180°to the normal of the substrate surface （B type）, indicating the mixture of A-and B-type crystallites in the top Si film. In the case of Si/CaF2/Si （111） structure the minimum yields of channeling along all directions are much higher than those in CaF2/Si （111） because the top silicon film are formed by A-and B-type crystallites and twinned. The misalignment of off-normal axes CaF2 （110）（or ） relative to the substrate Si （or ） indicates the existence of strain at the CaF2-interface r

关键词： epitaxial growth crystallite ion channeling.